Atauro - Pinnacle

General benthic features

The habitat the four frames reviewed in detail show is patchy and encruster-dominated rather than a coral carpet. The widest frame is a reef top of dark maroon algal turf and framework with corals scattered across it: cream-tan massive lobate coral heads, pale gray plating colonies, small pale corymbose and digitate colonies, a vivid red barrel-like sponge and a maroon sponge, patches of open sand behind, and many gray feathery plumes across the foreground, mostly hydroids, with one or two feather stars among them (e.g., Image 1).

1

A second wide frame is the sponge-and-foliose face of the site: several large pale-cream tightly convoluted foliose colonies, prominent dark gray finger and tube sponges with open oscula, brown tubular sponges, red and purple encrusting sponges, pink-mauve encrusting corals, more crinoids, and a single small white patch that could be a bleached nubbin or a chip of dead skeleton — not resolvable from the photograph (e.g., Image 4).

4

The third frame is a large tiered plating colony in dark purple-gray with a distinctly beaded surface, stacked in overlapping plates over sediment-dusted rubble, with a smoother lavender plate alongside and small hydroid tufts growing on it (e.g., Image 3).

3

The fourth is the most telling for cover: one solitary gray-green plate colony sitting on open, sediment-veneered hardground crusted with pink and red coralline algae, ringed by small blue damselfishes, with essentially no other living coral in frame (e.g., Image 2).

2

Cover varies locally, from frames with almost no living coral to frames with denser patches (no photograph scored above 45% coral in the point count), though most of the site reads as open.

Coral cover

• Reference: Claude CV point count (this site's photos)
• Coral cover: 20% — a blind Claude computer-vision point count of 53 of Anderson's edited photographs (20 points per photo; water, fish, and obstructions excluded). Other computer-vision methods are listed in the method table.

Stressors

Anderson photographed four bleached colonies on this dive: a fine-branching colony stark white except for an olive-yellow center, a plating colony with a sharply bounded white patch on one lobe, and two folded gray-white lobed soft corals on a mixed reef face (photos not shown). No transect tape, mooring, gear, or other man-made object appears; no disease lesion or predation scar is visible.

Fish and other fauna

Dark chromis hang in the blue, with a yellow-tailed snapper- or grouper-like fish and a small butterflyfish over the reef.

Comparisons with other data

Reef Check surveyed a nearby station (South of Tanjung Reta), 0.38 km from the pin; we could not confirm that it is the same reef. Within 5 km, twelve independent stations recorded station-year means of 13–65% hard coral cover between 2004 and 2017; the nearest, Reef Check at South of Tanjung Reta, 0.38 km away, read 33% in 2004.

Dive record

Pinnacle was dived on 31 January 2024, in at 08:28 for 46 minutes, 35.7 m maximum and 16.8 m average depth, average water temperature 27.7°C, and the frames look it: light is dim and blue-green rather than bright.